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C-21

Mission

The C-21 is a twin turbofan-engine aircraft used for passenger and cargo airlift. The aircraft is the military version of the Learjet 35A business jet. In addition, the aircraft is capable of transporting one litter or five ambulatory patients for aeromedical evacuation operations.

Features

The turbofan engines are pod-mounted on the sides of the rear fuselage. The swept-back wings have hydraulically actuated single-slotted flaps. The aircraft has a retractable tricycle landing gear, single steerable nose gear and multiple-disc hydraulic brakes.

The C-21 can carry eight passengers and 42 cubic feet (1.26 cubic meters) of cargo. The fuel capacity of the C-21 is 931 gallons (3,537.8 liters), with refueling accomplished at ground level through each wingtip tank. Safety and operational capabilities of the C-21 are increased by the autopilot and color weather. The aircraft has a crew of two and may be flown from either cockpit seat.

Background

Delivery of the C-21 fleet began in April 1984 and was completed in October 1985. C-21s stationed outside the Continental United States, or CONUS, were assigned to the theater commanders. Air Mobility Command at Scott Air Force Base, Illinois, is the lead command for the aircraft.

In April 1997, the majority of CONUS-based C-21s were consolidated within the 375th Airlift Wing at Scott AFB, while the National Guard Bureau maintained several aircraft at Peterson Air Force Base, Colorado, Air Force Flight Standards Agency maintained several aircraft at Joint Base Andrews, Maryland and Air Education and Training Command maintained several aircraft at Keesler Air Force Base, Mississippi.

In January 2007, Program Budget Decision Number 720 reduced C-21 operations to 40 aircraft. AMC dissolved C-21 operations at Wright-Patterson Air Force Base, Ohio. U.S. Air Forces in Europe was reduced from 13 to 10, Pacific Air Forces from four to three and AETC from five to three.

The NGB picked up 19 aircraft for ‘bridge’ missions at Fargo, North Dakota, Battle Creek, Michigan, and Bradley Air National Guard Base, Connecticut, until they received C-27 aircraft. Base Realignment and Closure actions moved the AFFSA C-21s from Joint Base Andrews to Will Rogers World Airport, Oklahoma City, Oklahoma. In June 2007, Pacific Air Forces divested itself of its three C-21s, the NGB gaining them.

In 2010, Resource Management Decision 700, or RMD 700, cut the number of C-21 aircraft from 56 to 28. Also, in line with RMD 700, AETC closed the flight training unit located at Keesler Air Force Base, Mississippi.

Beginning in 2018, the C-21 fleet in the United States began further consolidation efforts from Peterson AFB, Joint Base Andrews, moving all CONUS-based C-21s to Scott AFB’s 458th Airlift Squadron via the National Defense Authorization Acts of fiscal year 2018 and fiscal 2019.

These consolidation efforts leave Scott AFB’s 458th Airlift Squadron (AMC) and Ramstein Air Base, Germany’s 76th Airlift Squadron (USAFE) as the remaining force of C-21s. In addition, the first major upgrade in the fleet’s history is a $38 million “Avionics Upgrade Program” to modify all aircraft to a ‘glass cockpit’ configuration and meet 2020 global airspace equipment requirements.

General Characteristics

Primary Function: Passenger and cargo airlift

Manufacturer: Learjet, Inc.

Length: 48 feet, 7 inches (14.71 meters)

Height: 12 feet, 3 inches (3.71 meters)

Wingspan: 39 feet, 6 inches (11.97 meters)

Maximum Load:

Eight passengers and 3,153 pounds (1,433 kilograms) of cargo, or one litter patient or five ambulatory patients.

Power Plant: Two Garrett TFE-731-2-2B turbofan engines

Thrust: 3,500 pounds each engine

Maximum Takeoff Weight: 18,300 pounds (8,235 kilograms)

Fuel Capability: 931 gallons (3,537.8 liters) [1,120 gallons (4,256 liters) with ferry tanks]

Speed: 530 miles per hour (Mach 0.81, 461 knots at 41,000 feet (12,496.8 meters)

Ceiling: 45,000 feet (13,716 meters)

Range: 2,306 miles (3,689.6 kilometers)

Crew:

Two (pilot and copilot); aeromedical evacuation adds medical crew of three (one flight nurse and two medical technicians). Minimal medical crew may be one flight nurse, and one medical technician as required

Unit Cost: $3.1 million (Fiscal 1996 constant dollars)

Date Entered USAF Inventory: April 1984

Inventory: Active-Duty: 19; Air National Guard: 0; Air Force Reserves: 0

(Current as of April 2025)